Lab 5: Projections in ArcGIS

Using projections is an efficient way to visualize the earth. Since the earth is a sphere, it is difficult to observe it unless it is projected in a way that lets us see it as a plane. Thus, we must distort the earth in different shapes and sizes which ultimately distorts its true distances and areas. The true shape of the earth as well as its continents are not going to be retained and thus, they will be skewed in different way. The different types of projections that we observe in this lab are: Conformal, Equal Area and Equidistant.
Conformal maps keep the latitude and longitude lines at angles instead of curving them as seen in the first two map projections. Area and distance are not retained in these map projections however. As seen in the Mercator map, areas further from the equator are stretched and are more distorted due to its cylindrical projection. It is best used for projection.
Equal area map projections are able to preserve the actual area of land on these projections. For both the sinusoidal and the Bonne map projection, the areas of the continents are equal in size to their actual land mass. However, the areas away from the central point are much more distorted such as in the Bonne map projection, Africa seems to be the least distorted as it in the center focus of the map projection.
Equidistant map projections preserve distance. It portrays the distance from the center of the map to other place on the map. These maps are used for radio and seismic mapping. The equidistant cylindrical map projection have equally spaced longitudes and latitude lines.
Map projections should be selected based on what you are observing on the map projections. Different map projections are more catered to specific purposes such as certain continents are different navigational purposes. There are some projections that are created to observe certain areas and distances. Such as observing the distance from two cities, different map projections will show a different area where some are more accurate than others.